Hydraulic weighing device



Sept. 14, 1937. w, so sAL 2,093,141

HYDRAULIC WEIGHING DEVICE Filed April 11, 1934 ll 9 1,. z r 5 4 5 6 I 1/ INVEFITD P bi/dlllemiv fan/6621A- QQM - a m attainable there y Patented Sept. 14, 1937 umrso s'rA'rss PATENT OFFICE I mumcfizi imo DEVICE Waldemarlmsalla.

. Application April 11, m4. Serial No. mass In GermanyApr-Il 88, 1983 l 1 Claims. (01. 288-41) m. inventionreiates to ahydrauiic wei hing device. in which the load acts on several separate fluid pressure chambers the pressure in which is transmitted by separate pipings to a number a of auxiliary pistons which Jointly influence the same indicating device.

The known devices of this class have the draw-' backthat the transmission of power from the individual chambers to the auxiliary pistons can I. be disturbed by losses due toleakage andfrictionortoothercausesandthm errorsoccurin indicating theresult of the weighing process.

It was hitherto customaryto dispense with the interposition of'auxiliarypistonsin hydraulic is weighing devices provided with diaphragms and to connect the indicating device directly with the conduit system which united all individual chambers. 'A construction of this kind. however,

wilipermit areliabie ascertainment of wemht onlyift'hecenterofgravityoftheloadisiocated exactly above the center oithe weighing table so as to insm-eabeoiute uniformity in the loading.

of all chambers, but this condition cannot be fulfllled as a rule. In any case, in weighing devices of the kind described-,- which operate with auxiliary pistons, diaphragms have hitherto not been employed for the individual chambers and under the auxiliary pistons. so that the advan- Ihe arrangement of diaphragms under the auxthe fact that a plurality these pistons must act on a common indicating device without aifecting 35 thereby the accuracy of the weighing process.

The invention solves this problem by employing. in known manner. diaphragms above the pressure chambers of the carrying pistons of the individual scales and. for the purpose of provida ing similar diaphragms above the pressure chambers on which the other pistons act, transmitting the motion of the auxiliary pistons to a meas-' urin'g, gauge piston by means of rods disposed outside the coaxiaily arranged pressure chambers.

50 fled form.

Referring to the the table or mo.- I for receiving the load rests on a plurality of carryin pistons Leachof which'is 8 90 by a diaphragm I shutting off the top of a prespressure oil space or Ilsureoilchamberl. Each rted 1 chamber 4 is connected with a second pressure oil space I by a pressure oil conduit I.

The chambers I are arranged vertically above one another and closed on top by the diaphragms I, each of which carries an auxiliary piston I or 5 I. The auxiliary pistons I each contact one of the chambers I while the auxiliary piston I is the uppermost one and contacts with the transmissionplate II and the piston II, The auxiliary pistons I and I are provided at several points with lateral projections II which balance one another and which carry the supporting rods II. .The supporting rods II of all auxiliary pistons I extend up to the transmission plate II of the measuring. gau e piston II which abuts it from below against the diaphragm II shutting oil the pressure oil chamber II underneath. The chamber II is connected with a manometer II in known manner.

- It will be evident from the foregoing dcscription that a load placed on the plate I will be transmitted by means of the pistons 2 more or less uniformly, though usually to diil'erent extents. to thediaphragms I, and then act through the hydraulic connecting conduits I on the aux- 2 iliary pistons I and I which will thus be lifted. The lifting power is then transmitted by the rods II to the measuring gauge piston II and summed up and indicated by the manometer II, it being immaterial whether one piston 2 or sev- 80 eral or all of them-are aifected by the loading of the plate I. Those auxiliary pistons I and I whose carrying pistons 2 remain unloaded are not affected by the weighing process and do not exert pressure upon the measuring gauge piston it during the ascent of the latter, which is an important feature. as the sensitiveness of the weighing device and the accuracy of weight indication, especially in case of small loads, are increased thereby. 40

The device Just described aflords the considerable advantage that losses due to leaks are excluded or, at least, cannot, make themselves felt to a disturbing degree.

Accordingto the invention. the construction 46 described can further be considerably simplified andimproved as to measuring accuracy by employing the auxiliary pressure spaces themselves for transmitting the pressure oil forces eil'ective therein to the measuring gauge piston. 50

In this case (Fig. 2) the weighing table or plate I rests as beforeonthe carrying pistons 2 which t the load through the diaphragms I to the fluid in the pressure oil chambers I. The latter transmit the pressure by means of the conduits 5 to the pressure fluid filled into the auxiliary chambers 6 which are coaxially arranged. Each chamber 6 is closed on top by .a diaphragm 1 on which an auxiliary piston 8 rests. The diaphragms 1 are secured to the chambers 6 by the holding rings [8, and the pistons 8 are approximately as high as the holding rings [8 and guided in the latter, the general arrangement being such that after the plate I isrelieved the chambers 6, are directly supported by the holding rings i8 disposed underneath them. If the plate I is loaded, the individual pistons 8 will rise in accordance with the hydraulic forces that are effective in the pressure oil chambers dis-' posed underneath them, and will then lift the superposed auxiliary chambers 6 off from the holding rings I8. In other words, the hydraulic forces effective in the various auxiliary chambers 6 will be transmitted by the pistons disposed above their respective diaphragms to the next higher auxiliary chamber 6 and'by the latter to the superposed parts of the measuring device.

The-uppermost auxiliary piston 9 transmits all the forces acting on it to the directly 'super posed measuring gauge piston I3, whichin'turn transmits the total force H to the pressure medium in the pressure oil chamber iii of the the indication thereof by the instrument i6.

Foundation bolts 20 connecting the head piece l9 with the lowermost'auxiliary chamber 6 serving also as base insure lasting union of the parts and further permit the maintenance of a certain initialpressure in the pressure oil chamber 15 whereby the pointer of the manometer I6 is i placed in zero position.

To prevent lateral displacements of the auxiliary chambers 6 relative toone another it is advisable to have the holding rings [8 engage" corresponding depressions in the superposed auxiliary chambers 6 or the piston l3.

The connecting conduits 5 are wholly or partly to be able toiollow of the auxiliary chambers 6. All

flexible or articulated so as displacements auxiliary chambers 6 are surrounded by a common sheet metal cylinder 2|. l I claim:. 1

1. A hydraulic weighing device, comprising, a

load receiving plate, a plurality .of pistons for sustaining said plate, a fluid pressure chamber under each piston, a diaphragm for closing the top of each pressure chamber and supporting one of said pistons, auxiliary fluid pressure chambers arranged vertically above one another, conduits connecting each of said first fluid pressure chambers with one of sure chambers, a diaphragm for closing'the top of each auxiliary fluid pressure chamber, an aux iliary piston having lateral projections and being carried by each of said second-mentioned diaphragms, a measuring gauge piston abutting against the uppermost auxiliary fluid'pressure chamber, said measuringpiston being coaxial with said auxiliary fluid pressure chambers, rods disposed on the projections of said auxiliary pistons and connecting the latter with said measuringpistonto transmit thereto the power raising said auxiliary pistons, and a manometer conthrough the diaphragm head piece l9 and thus causes chambers to said auxiliary fluid pres under each piston, top of each pressure chamber and supporting one of said pistons, coaxially arranged auxiliary fluid pressure chambers, corresponding in number to the sustaining pressure chambers, conduits connecting said sustaining pressure chambers and transmitting the pressure exerted by a load to said auxiliary chambers, diaphragms for closing the top of each auxiliary pressure chamber, separately movable pistons on said diaphragms, holding rings for securing said diaphragms to said auxiliary pressure chambers, said pistons being approximately equal in height to said rings and guided therein and in contact with the auxiliary fluid pressure chamber disposed above them, a measuring gauge p ton to which the pressure exerted by a load is transmitted by the uppermost separately movable piston, said measuring gauge piston abutting against the diaphragm shutting ofi the fluid pressure space disposed on top of the device, a manometer connected with said topmost fluid pressure space for indicating the pressure exerted by the load, and means for maintaining the separ tely movable pistons coaxial.

3. A hydraulic weighing device according to claim' 2, in which the holding rings engage depressions of superposed auxiliary fluid pressure prevent lateral displacement of the latter. v r

4. Hydraulic weighing device comprising a load receiving plate, a-plurality of pistons for sustaining said plate, a fluid pressure'chamber under each piston, a diaphragm for closing the top of each pressure chamber and each sup-,-

porting one of said pistons, auxiliary fluid pres-4 surechambers corresponding in number to .the

sustaining pressure chambers and arranged ver-.

tically above one another, conduits connecting each sustaining pressure chamber with one of said auxiliary: fluid pressure chambers, a diaphragm. for closing the top of, eachauxiliary fluid pressure chamber, separately movablepise tons one being carried by each of.said secondmentioned diaphragms, ameasuring gauge piston coaxial with saidauxiliary pressure chambers and abutting against the uppermost aux iliary piston, means to transmit thrustifrom each of, the other saidauxiliary pistons to said measuring gauge piston, a measuringgaugepressure chamber for said measuring gauge piston, a manometer connected with said measuring gauge pressure chamber for indicating the power requiredto raise said auxiliary pistons, and means.

6. A hydraulic weighing device according to claim 4, in which the thrust means comprise rods attached to the auxiliary pistons and abutting freely against the measuring piston, and in which the auxiliary fluid pressure mounted in a housing having guide means for the rods.

7. A hydraulic weighing device according to claim 4, in which the thrust means comprise rods attached to the auxiliary pistons and abutting measuring piston.

WALDEMAR SONSALLA.

freely against the a diaphragm for closing the device according to chambers are 

